Method of Routing a Call Made to a Fixed Telephone Number of a UMA-Subscriber in a Telecommunication Network

ABSTRACT

The invention relates to a method of routing a call made to a fixed telephone number of a UMA-subscriber in a telecommunication network. A service control entity stores a so-called ‘near list’ comprising a cell identifier of each cell overlapping a WLAN coverage area of a WLAN AP associated with the UMA-subscriber. The service control entity also receives location information of the UMA-subscriber from a switching node ( 2 ) or from a location server ( 16 ). If the cell identifier of the serving cell is in the near list, the service control entity prompt the caller to select out of a list of options. If the cell identifier of the serving cell is not in the near list, the caller will be prompted but with a different message and with different options to select. The caller is for example offered the opportunity to wait for the called party to arrive at home, and be dialed back.

TECHNICAL FIELD

The present invention relates to a method of routing a call made to afixed telephone number via a mobile telecommunication network. Thepresent invention also relates to a telecommunication network and aservice node arranged to execute (part of) the method.

BACKGROUND

Recently, mobile telephone services were introduced wherein a subscriberonly needs one single mobile phone that is suitable for calling viaVoice Over IP (VOIP) and via GSM/UMTS. If the subscriber resides athome, she may call via a radio based connection like Wireless Local AreaNetwork (WLAN), Wireless Fidelity (WIFI), or Bluetooth. These radiobased connections are collectively denoted as UMA (Unlicensed MobileAccess). GSM, UMTS and the like are denoted as GAN (Global AccessNetworks). Phones capable of connection in both UMA and GAN are denotedas UMA/GAN phones. For a subscriber to use the phones capabilities sheneeds to have either GAN and UMA subscriptions or a combined UMA/GANsubscription. Below, it is assumed that a subscriber has a combinedUMA/GAN subscription. Such a subscriber is simply referred to as aUMA-subscriber.

In co-pending patent application PCT/NL2006/050279 a method of routing acall made by a calling party to a fixed telephone number of a calledparty is described. The call is routed to a mobile terminal via anInternet Protocol (IP) network and a WLAN access point (AP) associatedwith the fixed telephone number only when the mobile terminal is locatedin an area covered by the WLAN AP. The call is routed to an alternativeterminating point, such as a voicemail system, if the mobile terminal islocated outside the WLAN coverage area. The basic idea ofPCT/NL2006/050279 is to provide subscribers with a fixed telephonenumber the facility to route calls that are made to the fixed telephonenumber either to a mobile phone of the subscribers when they are locatedin a so-called ‘Home Zone’, or else to an alternative terminating point,such as a voice mail of the subscriber that may reside in thetelecommunication network of a telecom provider. A Home Zone isdetermined by an area which is covered by one or more wireless accesspoints. The service which is provided to the subscribers is alsoreferred to as the ‘@home service’.

SUMMARY OF THE INVENTION

A goal of the present invention is to improve the method of the state ofthe art.

This goal is achieved by providing a method of routing a call made to afixed telephone number of a UMA-subscriber in a telecommunicationnetwork comprising a switching node, a location server and anintelligent network, the intelligent network comprising a servicecontrol entity, wherein said service control entity:

stores a list associated with said UMA-subscriber, said list comprisinga cell identifier of each cell overlapping a WLAN coverage area of aWLAN AP associated with said UMA-subscriber;

receives a trigger message from said switching node, said triggermessage comprising said fixed number of said UMA-subscriber;

receives location information of said UMA-subscriber from said switchingnode or from said location server, said location information comprisinga cell identifier of a cell serving said UMA-subscriber;

performs a first action if said cell identifier of said serving cell isin said list, and a second action, different from said first action, ifsaid cell identifier of said serving cell is not in the list.

By defining an area ‘near home’ a caller can be informed about the factthat the called party is almost at home. The caller is for exampleoffered the opportunity to wait for the called party to arrive at home,and call again or be dialed back.

In a further aspect, the invention relates to a service control entityfor providing intelligent network services to users of a mobiletelecommunications network, the mobile telecommunications networkcomprising a switching node and a location server, the service controlentity being connectable to the switching node and to the locationserver, the service control entity comprising a processing unit, aninput unit connected to the processing unit and an output unit connectedto the processing unit, wherein the processing unit is arranged to:

store a list associated with the UMA-subscriber, the list comprising acell identifier (CI) of each cell overlapping a WLAN coverage area of aWLAN AP associated with the UMA-subscriber;

receive a trigger message from the switching node, the trigger messagecomprising the fixed number of the UMA-subscriber;

receive location information of the UMA-subscriber from the switchingnode or from the location server, the location information comprising acell identifier of a cell serving the UMA-subscriber;

-   -   perform a first action if the cell identifier of the serving        cell is in the list, and a second action, different from the        first action, if the cell identifier of the serving cell is not        in the list.

In a further aspect, the invention relates to a telecommunicationnetwork comprising a service control entity as described above.

Finally, the invention relates to a computer program product comprisingcomputer executable code, which when loaded on a computer system, allowsthe computer system to execute the method mentioned above.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be discussed in more detail below, using anumber of exemplary embodiments, with reference to the attacheddrawings, in which:

FIG. 1 shows a network diagram which depicts part of a telecommunicationnetwork according to an embodiment of the invention;

FIG. 2 shows a flow chart of actions taken by an SCP according to anembodiment of the invention;

FIG. 3 shows an example of coverage areas of a WLAN and four BTSs;

FIG. 4 shows a possible structure of network units SCP, HLR and the MSC.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

In FIG. 1, a network diagram is shown which depicts part of atelecommunication network 1 according to an embodiment of the invention.In this simplified example, the telecommunication network 1 comprises aMobile Switching Centre (MSC) 2, a Base Station Controller (BSC) 4 whichcontrols two Base Transceiver Stations (BTSs) 6, 8. A more generic termfor MSC is ‘switching node’. Furthermore, the network 1 comprises a UMC10 and a WLAN AP 12, such as a WiFi enabled modem installed at theUMA-subscriber premises. The telecommunication network 1 also comprisesa service control entity, in this example Service Control Point (SCP)14, and a location server, in this example Home Location Register (HLR)16. The SCP 14 is the platform on which Intelligent Network (IN)applications are running, as will be clear to the skilled person. AService Switching Functionality (SSF) is arranged in the MSC 2.

In FIG. 1, a UMA/GAN phone, also referred to a Mobile Station (MS) 18,is depicted which is arranged to communicate both via the WLAN AP 12 anda serving BTS, in this example the BTS 8. If the MS 18 is in a WLANcoverage area of the WLAN AP 12, it will receive calls via the WLAN AP12 and the UMC 10. How a call is routed to the UMA/GAN phone 12 will bedescribed below in more detail.

In the event where a calling party sets up a call using a fixed number,the MSC 2 receives a ISUP IAM message from a Gateway MSC (not shown inFIG. 1). The fixed number is the CalleD Party Number (CdPN) in the ISUPIAM message. The MSC 2 will perform number analysis and next the SSF inthe MSC 2 will trigger the SCP 14 whenever a connection needs to be setup to the fixed number. To set up a connection, at the signalling level,a phone number is transmitted via the network. There are three basicways in which number analysis can select which called numbers to forwardto the SCP 14. A first way is known as “all B or all query” In this casenumber analysis will forward every called number to the SCP 14.Alternatively, number analysis comprises a list of phone numbers forwhich first the SCP 14 is accessed to check whether the finaldestination is correct, before the call is connected to the finaldestination. Instead of a list of phone numbers also a range of phonenumbers or a subscription class of the phone numbers may be used. If forexample, a called party has forwarded all the calls to another number,the SSF will ask the SCP 14 for every call to which number the callneeds to be connected.

According to an embodiment, number analysis stores a list ofUMA-subscribers for which the @home service on the SCP 14 needs to betriggered. In the case that a call will be established to an UMAsubscriber, the location of the mobile phone of the UMA subscriber willbe checked. There are several ways to check the location of this mobilephone. One of the options is that the SCP 14 send a MAP-ATI message(MAP-AnyTimeInterrogation) to the HLR 16 via the SSF in order to getlocation information of the called party. The HLR 16 will return thelocation information to the SSF in a MAP message. The SSF will then sendthe location information to the SCP 14 so that the @home service on theSCP 14 can perform appropriate actions as will be explained below. It isnoted that instead of ‘@home’, the concept ‘@office’ or @Club may bedefined implying that an area is defined which is covered by one or moreWLAN APs situated in e.g. an office, club or factory, etc.

The present invention makes use of a number of location relateddefinitions: Cell global identifier (CGI), Location area identifier(LAI), Location number (LN) and Location information (LI). Thesedefinitions are specified by 3GPP as follows:

CGI=MCC+MNC+LAC+CI  (1)

with

MCC=mobile country code;

MNC=mobile network code;

LAC=location area code;

CI=cell identifier.

The CGI is a globally unique identifier for a cell in a GSM radio accessnetwork. See 3GPP TS 23.003 v7.3.0, section 4.3.1.

LAI=MCC+MNC+LAC  (2)

The LAI is a globally unique identifier for a location area in a GSMradio access network. A LAI comprises one or more CGI's. See 3GPP TS23.003 v7.3.0, section 4.1.

The LN is an E.164 number that is used to identify a location in amobile network. The LN is structured as follows:

LN=CC+NDC+LSP  (3)

with

CC=country code;

NDC=national destination code;

LSP=locally significant part.

See also 3GPP TS 23.003 v7.3.0, section 4.5.

The Location Information (LI) is a set of location elements describingthe location of a subscriber in a mobile network. Depending on the typeof mobile network, the LI consist of one or more of the followingelements:

-   -   CGI or LAI    -   LN    -   VLR address        The above list is not exhaustive. For a complete description of        LI, refer to 3GPP TS 23.018 v7.4.0, section 8.3.5.1.

When the UMA-subscriber using the MS 18, see FIG. 1, is attached to theMSC 2 via WLAN (i.e. UMA access), then this is reflected in her CGI,consisting of the MCC, MNC, LAC and CI, see formula (I). The UMA accessfor the MS 18 is gained through the UMC 10. The UMC 10 behaves as a BSCtowards the MSC 2 to which it is connected. The UMC 10 has a LACassociated with it. The LAC of the UMC 10 together with an MCC and MNCof the Mobile Network form a LAI associated with the UMC 10. When theUMA-subscriber attaches to the MSC 2 through the UMC 10, then her CGI isreported to the MSC 2. If the UMA-subscriber is under GSM access, theBSC 4 takes the place of the UMC 10. The BSC 4 also has a LAC allocatedto it, which is reported to the MSC 2.

According to an embodiment, the SSF sends the UMA-subscriber's CGI tothe SCP 14. The @home service on the SCP 14 will then produce a connectmessage meant for the MSC 2 so as to connect the call to the appropriateterminating point.

FIG. 2 shows a flow chart depicting a method performed by the @homeservice according to an embodiment of the invention. The method startsby receiving a CAP message from the SSF, said CAP message comprising theCalled Party Number (CdPN) and Location information of this terminatingsubscriber, see step 201. The @home service will first test whether thecalled UMA-subscriber is reachable by either GSM/UMTS or WLAN, see step202. If the UMA-subscriber is not reachable by GSM/UMTS, a further testfollows in a step 203 to see whether the UMA-subscriber is reachable viaWLAN. If this is not the case, the UMA-subscriber is currently in aradio silent area or she has her mobile switched off. The @home servicewill now proceed with a step 204 and will send a voice message to thecalling party saying that there is no connection possible. Next, in astep 205, the caller will be prompted and he will be asked to select oneof the available options;

1. Dial back when called part returns @home or @office

2. Dial back when current conversation has ended

3. Dial back when either WLAN or GSM/UMTS connection is restored

4. SMS notification when called party near home or office

5. SMS notification when called party @home or @office

6. SMS notification when either WLAN or GSM/UMTS connection is restored

7. Put through to GSM/UMTS and bear cost for 2nd leg of the connection

8. Leave voice message.

If the called party is not reachable, the calling party can only selectoptions 3, 6 or 8 out of the above mentioned list. If the calling partyselects option 3, the method proceeds with a step 206 in which a callback event is produced. This call back event is then registered in theSCP 14 in a step 207. Finally, in a step 208 a Disconnect message issend back to the MSC 2.

If in step 205 the calling party selects option 6, an SMS notificationis produced in a step 209 and the SMS notification is then registered instep 207. If the calling party selects option 7, the @home service willconnect the calling party to the UMA-subscriber via the GSM (or UMTS)mobile network, see steps 210 and 211. The costs for the so-called2^(nd) leg will then be charged to the initiating (i.e. calling) party.If in step 205 the calling party selects option 8, the @home serviceforwards a voice mail number to the MSC 2 and sends a Connect message,see steps 212 and 211.

If it turns out in step 203 that the UMA-subscriber is reachable byGSM/UMTS, a step 215 follows in which it is tested whether theUMA-subscriber is busy (engaged in another conversation). If this istrue, a step 216 follows in which a message ‘Party is currently busy’ issend to the calling party. The calling party is then prompted in step205 and the calling party may selects one of the options 2 or 8 out ofthe list of available options listed above. If he selects option 2, step206 follows and step 207 and step 208. If he selects option 8, step 212follows and then step 211.

If the outcome of the test in step 203 is ‘Yes’, the method proceedswith a step 213 in which a connection is made to the UMA-subscriber viathe UMC 10 and the WLAN AP 12.

If the outcome of the test in step 215 in FIG. 2 is ‘No’, a furthertest, see step 218, follows in order to find out if the UMA-subscriberis near home. The @home service will compare the cell identifier (CI) inthe Location information of the UMA-subscriber with CIs present in alist referred to as the “near list” associated with the UMA-subscriber.The near list comprises the CI of all the cells which at least partlyoverlap (with) the WLAN area of the UMA-subscriber.

If the UMA-subscriber is reachable by GSM/UMTS but not reachable byWLAN, and current radio CI is not in the “near” list, a step 219 followsin which a voice message is sent to the calling party saying that “thecalled party is currently outside home area”. The calling party will beprompted, see step 205, and may selects options 1, 4, 5, 7 and 8 out ofthe above mentioned list.

If in step 218 the UMA-subscriber is in a radio cell with CI that is inthe near list of the UMA-subscriber, a step 220 follows in which istested whether the UMA-subscriber is ‘at home’, i.e. has WLAN access. Ifthe UMA-subscriber is ‘at home’, step 213 follows and the SCP 14 willsend a Connect message to the SSF in order to connect the call via theWLAN AP 12 shown in FIG. 1. If however in step 220 it is concluded thatthe UMA-subscriber is not ‘at home’, she must be ‘near home’. This iscommunicated to the caller in step 221. The caller will be prompted toselect one of the options 1, 5, 7, 8.

After step 211, the SSF will receive the correct number from the SCP 14and will establish a connection to the correct number. Please note thatthe term ‘number’ is not necessary the same as ‘telephone number’. Avoice mail box associated with a telephone number will have in thenetwork a different ‘number’ than the telephone.

Below, the status of the UMA-subscriber in the example of FIG. 2 issummarized:

-   -   A. Not reachable by either GSM/UMTS or WLAN (radio silent area        or mobile is switched off)    -   B. Not reachable by GSM/UMTS but reachable by WLAN (inside        building no GSM/UMTS coverage)    -   C. Busy (engaged in an other conversation)    -   D. Reachable by GSM/UMTS but not reachable by WLAN, and current        radio cell-ID is not in the “near” list    -   E. As above but now the radio cell-ID is in the near list

The possible announcements of steps 204, 216, 219 and 221 are:

I. Party has currently no connection (switched off or radio silent area)

II. Party is close to home or office zone

III. Party is currently outside home or office area.

IV. Party is currently busy

In table 1, an overview is shown with possible announcements andselections in the example of FIG. 2.

TABLE 1 Subscriber Options status Announcement available A I 3, 6, 8 BConnection to subscriber C IV 2, 8 D III 1, 4, 5, 7, 8 E II 1, 5, 7, 8

In the previous embodiment, a single UMA-subscriber was taken asexample. According to another embodiment, the SCP 14 stores a list ofUMA-subscribers (also referred to as group members) belonging to oneso-called ‘hunting group’. Such a list is referred to as ‘hunting list’.In this embodiment, some of the options listed in table 1 are notmeaningful as will be apparent to the skilled reader.

Each group member by itself has a status A-E as described in theprevious example. These are now however combined. Call back or SMSnotification get a slightly different meaning as they apply to any oneof the group members rather then one specific member. Engaged in aconversation means that each group member is engaged. Below, a list ofpossible status is shown:

-   -   A. none of the group members are inside radio coverage of either        GSM/UMTS or WLAN.    -   B. there is at least one group member reachable via WLAN        irrespective if others have GSM/UMTS connection or not    -   C. all of the group members having WLAN connection are engaged    -   D. none of the group members having GSM/UMTS connection is in a        cell that is covering their individual WLAN area    -   E. at least one group member from the group having GSM/UMTS        connection is in a cell covering an individual WLAN area, and no        member of the group is WLAN connected.

An overview is given in table 2.

TABLE 2 Is any mobile of group GSM/UMTS connected? N * * Y Y Is anymobile of group WLAN connected? N Y Y N N Is any mobile of group notbusy? — Y N Y Y Is any mobile of group in ‘near home’ ? — * * N Y StatusA B C D E *= don't care — = not valid

In order to be able to select a prompt and collect announcement, the SCP14 according to an embodiment makes a first check on the possiblesubscriber-numbers in the hunting list whether they have currently WLANconnection and/or GSM connection. A sub list “WLAN” and the sub list “noWLAN but GSM” is filled by the SCP 14. If sub list “WLAN” and the sublist “no WLAN but GSM” are both empty, then case A applies, see table 2.If all subscribers are busy or do not answer for the B-number in theWLAN list then case C else case B a connection is made. When only thesub list “WLAN” is empty, then a check is made to see if any of thesubscribers is in the radio cell that corresponds with the WLAN access,i.e. is ‘near home’. If none are ‘near home/office’, then case Dapplies, else case E applies and an announcement is made saying e.g.“(one of the) subscribers is near home/office”. Basically the samemessages and options can be used as the embodiment with a singlesubscriber. In case several mobile numbers (MSISDN's) are associatedwith one fixed number (i.e. a hunting group is defined), the location ofall these mobile phones will be checked. There are two types of possiblehunting mechanisms:

-   -   Serial ringing (where connection will be tried to set-up one        after the other to all phones that are e.g. within WLAN        coverage).    -   Parallel ringing (where connection will be set-up simultaneously        to all phones that are e.g. within WLAN coverage).

In the embodiments described above, the SCP 14 receives locationinformation from the MSC 2 which has fetched this information from theHLR 16. Alternatively, the SCP 14 may receive the location informationfrom a HBSC (not shown). In this case, the SCP 14 will receive updatemessages from the HBSC that give the necessary information. The UMA/GANphone 18 is then registered as out the Home Zone, when there is noconnection.

FIG. 3 shows an example of coverage areas of a WLAN and four BTSs. AWLAN coverage area 301 is partly overlapped by cells 302, 303 and 304.Cell 305 does not overlap the WLAN area 301, see FIG. 3. In thissituation the list of cell IDs defining ‘near home’ comprises the CIs ofcell 302, 303 and 304 but not that of cell 305. If a calledUMA-subscriber using a MS 306 is in cell 304 but not in WLAN area 301,the calling party will receive a message ‘subscriber is near home’. Thismessage will be followed by a message inviting the calling party toselect one of the options 1, 5, 7 or 8 as was described with referenceto FIG. 2. When choosing options 1, 5 or 8, the Calling Party will savecosts as compared to option 7. If the calling Party selects option 1, hewill be connected to the UMA-subscriber if the UMA-subscriber is underWLAN coverage. In that case the call will be billed as being a mobile tofixed telephone call since the Calling Party has used a fixed number.This is less expensive than a mobile to mobile call.

The MSC 2, the SCP 14 and the HLR 16 may be implemented as network units901, the structure of which is shown in simplified form in FIG. 4. Thenetwork unit 901 comprises a processing unit 903 connected to an inputunit 902. Furthermore, the processing unit 903 is connected to an outputunit 904. These allow the processing unit 903 to communicate with othernetwork units 903 or other elements in the communication network. Theprocessing unit 903 may comprise a general purpose central processingunit (CPU) or a group of interconnected CPUs, or alternatively adedicated processing unit, e.g. a signal processing unit. A memorymodule 905 may also be provided and may be used to store data, but mayalso be used to store a software program comprising instructions, whichallows to use the processing unit 903 for various processing functions.E.g. it is possible that one network unit 901 under the control of asoftware program fulfils the function of the MSC 2 and at the same timethe function of the SCP 14.

The present invention has been explained above with reference to anumber of exemplary embodiments. As will be apparent to the personskilled in the art, various modifications and amendments can be madewithout departing from the scope of the present invention, as defined inthe appended claims.

1-9. (canceled)
 10. A method of routing a call made to a fixed telephonenumber of a UMA-subscriber in a telecommunication network that comprisesa switching node, a location server and an intelligent network, theintelligent network comprising a service control entity, said methodcomprising said service control entity: storing a list associated withsaid UMA-subscriber, said list comprising a cell identifier (CI) of eachcell overlapping a WLAN coverage area of a WLAN AP associated with saidUMA-subscriber; receiving a trigger message from said switching node,said trigger message comprising said fixed number of saidUMA-subscriber; receiving location information of said UMA-subscriberfrom said switching node or from said location server, said locationinformation comprising a cell identifier of a cell serving saidUMA-subscriber; and performing a first action if said cell identifier ofsaid serving cell is in said list, and a second action, different fromsaid first action, if said cell identifier of said serving cell is notin said list; wherein said first action comprises: checking if theUMA-subscriber is currently in said WLAN coverage area of said WLAN APassociated with said UMA-subscriber; and if the result of said checkingis affirmative, connecting the call to said UMA-subscriber via said WLANAP; or if the result of said checking is negative, sending a callingparty making the call a message indicating that the UMA-subscriber iscurrently in at least one of the cells of said list but not in said WLANcoverage area.
 11. The method of claim 10, wherein if the result of saidchecking is negative, said first action further comprises prompting thecalling party to select one out of at least one of the followingoptions: dialing back when UMA-subscriber is in said WLAN coverage area;receiving an SMS notification when said UMA-subscriber is in said WLANcoverage area; being put through to GSM/UMTS and bearing cost for secondleg of the connection; and leaving a voice message for saidUMA-subscriber.
 12. The method of claim 10, wherein said second actioncomprises: sending a calling party making the call a message indicatingthat the UMA-subscriber is currently in none of the cells of said list.13. The method of claim 12, wherein said second action furthercomprises: prompting the calling party to select one out of at least oneof the following options: dialing back when UMA-subscriber is in saidWLAN coverage area; receiving an SMS notification when saidUMA-subscriber is in at least one of said cells in said list; receivingan SMS notification when said UMA-subscriber is in said WLAN coveragearea; being put through to GSM/UNITS and bearing cost for a second legof a connection to said UMA-subscriber; and leaving a voice message forsaid UMA-subscriber.
 14. Method of claim 10, wherein said servicecontrol entity: stores a hunting list comprising MSISDN numbers of aplurality of mobile phones associated with said UMA-subscriber; receiveslocation information of each of said plurality of mobile phones fromsaid switching node or from said location server, said locationinformation comprising for each of said plurality of mobile phones, acell identifier of a cell serving said mobile phone; and performs saidfirst action if said at least one cell identifier is in said near list,and said second action, different from said first action, if none ofsaid cell identifiers are in said near list.
 15. The method of claim 10,wherein said telecommunication network further comprises a UMC connectedto said switching node and having an associated location area code(LAC), and wherein said UMC: reports said LAC to said switching nodewhen said UMA-subscriber attaches to said switching node through saidUMC.
 16. A service control entity for providing intelligent networkservices to users of a mobile telecommunications network, said mobiletelecommunications network comprising a switching node and a locationserver, said service control entity being connectable to said switchingnode and to said location server, and said service control entitycomprising a processing unit, an input unit connected to the processingunit and an output unit connected to the processing unit, wherein theprocessing unit is arranged to: store a list associated with saidUMA-subscriber, said list comprising a cell identifier, CI, of each celloverlapping a WLAN coverage area of a WLAN AP associated with saidUMA-subscriber; receive a trigger message from said switching node, saidtrigger message comprising a fixed number of said UMA-subscriber;receive location information of said UMA-subscriber from said switchingnode or from said location server, said location information comprisinga cell identifier of a cell serving said UMA-subscriber; and perform afirst action if said cell identifier of said serving cell is in saidlist, and a second action, different from said first action, if saidcell identifier of said serving cell is not in said list; wherein saidfirst action comprises: checking if the UMA-subscriber is currently insaid WLAN coverage area of said WLAN AP associated with saidUMA-subscriber; and if the result of said checking is affirmative,connecting the call to said UMA-subscriber via said WLAN AP; or if theresult of said checking is negative, sending a calling party making thecall a message indicating that the UMA-subscriber is currently in atleast one of the cells of said list but not in said WLAN coverage area.17. The service control entity of claim 16, wherein the service controlentity is included as part of said mobile telecommunication network.